1. Field of the Invention
The present invention relates to an anchor rod to be received in a bore filled with a mortar mass and having a connection region and an anchoring region provided with a plurality of axially arranged one after another, conical enlargements the diameter of which increases in a setting direction.
2. Description of the Prior Art
In addition to classical connection systems with which attachment points are formed by an expansion dowel which is form-and/or force-lockingly anchored in a bore, prior art discloses a chemical connection technology according to which an anchor rod is inserted in a receiving bore filled with a mortar mass and becomes secured there after hardening of the mortar mass. The advantage of the later connection systems consists in that they are free of expansion pressure to a greatest possible degree and, therefore, allow for small spacings between the axes and edges. For heavy duty attachments, connection anchor systems are used with which a multi-component organic and/or inorganic mortar mass fills a preliminary formed bore, with the components of the mortar mass being separated, before anchoring, by their glass or plastic packing. An anchor rod for use with such a system is disclosed in European Patent Publication EP-B-O-356425. The anchor rod, which is disclosed in this publication, is rotated about its longitudinal axis and is driven into a bore filled with components of a mortar mass. The insertable anchor rod destroys the packing in which the mortar mass components are contained. The rotatable anchor rod provides for more or less homogeneous intermixing of the components and comminution of the broken packing. The resulting load value of the attachment depends on the intermixing of the mortar mass components. To this end, in the past, a plurality of different designs of the anchor rod was proposed which should have insure an adequate intermixing of the mass components and comminution of the packing, without deactivating the mortar mass by overheating. The drawback of this technology consists in that the placing and handling of the mortar mass packing should be done with an utmost care, in particular with glass packing, to prevent the packing from being broken.
Also known are connection anchoring systems with which the mortar mass is preliminary mixed and is placed in a preliminary formed bore. Such connection anchoring systems which, e.g., are produced by the assignee of this application, are primarily used in brickwork, in particular, with the use of hollow bricks. Usually, a two-component mass is squeezed out of separate packings for the reactive components by a squeezing apparatus, is mixed in a mixing apparatus located in front of an outlet opening of the squeezing apparatus, and is injected in a bore which is preliminary formed in a brickwork. For better distribution of the preliminary mixed mortar mass and to prevent the mortar mass from penetrating into a hollow of a brick in which the bore is formed, the receiving bore is provided primarily with a sleeve having rupture points. To insure a complete filling of a receiving bore provided with a sleeve, the mortar mass should be injected toward the bore mouth from the base of the bore in accordance with a predetermined process. Then, the anchor rod is inserted into the bore filled with the mortar mass. After hardening of the mortar mass, the anchor rod, which is primarily formed as a thread anchor rod, becomes fixed in the bore. The load values, which are achieved in brickwork with the known attachment technology, depend primarily on the strength of the brick. During the attachment in a hollow material, e.g., in concrete, the achievable attachment values depend, in addition to adequate intermixing of the reactive components of the mortar mass, also on the position of the bore filled with a mortar mass. The filling of the bore with mortar mass components, which are stored in separate glass or plastic packings and are mixable only in the bore, can be relatively easily controlled. The viscosity of the mortar mass components is relatively low. This results in that upon being released from their packings, the mortar mass components flow, under their gravity forces, toward the back of a substantially more or less vertically extending bore. When the bore extend horizontally or is inclined upwards, or during an overhead mounting, the low viscosity presents substantial difficulties because the mortar mass flows out of the bore.
The mortar masses, which are mixed immediately before being injected into a receiving bore, have a high viscosity. Therefore, they are suitable for filling horizontal or upwardly inclined bores, as well as for the overhead mounting. However, a high viscosity can present a drawback for filling the bore. If the preliminary mixed mortar mass is not injected from the back of the bore to the bore mouth, it may happen that the bore would not be adequately filled with the mortar mass. In particular, in the region of the back of the bore, the anchoring region of the anchor rod can be inadequately embedded in the mortar mass, which negatively affects the achievable load values.
Accordingly, an object of the present invention is to provide an anchor rod to be received in a bore filled with a mortar mass which would insure an adequate filling of the back of the bore with the mortar mass having high viscosity.
Another object of the present invention is to provide an anchor rod which would insure as complete as possible embedding of the anchoring region in the mortar mass.
A further object of the present invention is to provide an anchor rod which can be used with a mortar mass the reactive components of which are mixed immediately before injection outside of a receiving bore.
A still further object of the present invention is to provide an anchor rod with which the danger of deactivation of the mortar mass, which fills the bore, as a result of overheating, is prevented.